Is this shot a good source of arsenic?

How much would you need to add to arsenic-free alloy to allow water-drop hardening?

http://www.rotometals.com/product-p/lead_shot_magnum_7.htm

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USSR

October 29, 2013, 02:17 PM

Totally depends upon the alloy you are adding it to. If you use an alloy such as that found with clip-on wheel weights, then you don't need to add anything because the wheel weights contain a little arsenic. If you are using a near pure lead alloy, then in addition to adding the shot, you will also need to add some lead containing antimony and some tin. What you want to end up with is an alloy containing > 2% antimony, .125 to .250 arsenic, and a little tin to aid in fill out.

Don

243winxb

October 29, 2013, 02:26 PM

An alloy needs a minimum of 2% antimony to water drop. Takes about 2 week to fully harden. If the % of antimony is higher, takes less time to be hardened. From mold to water is not as good as from oven to water. See LYmans website FAQ

Buck13

October 29, 2013, 10:39 PM

I should explain my question more fully:

I have a couple hundred pounds of 25# lead bricks, alloy unknown. They're a little harder and more silver than pure lead, purchased to ballast some equipment, but I don't know from whom. I was resistant to taking up casting, so I've shipped a couple boxes of them to other forum members in exchange for some finished bullets. One reported that it just needed a little tin added. I hit one of those bullets a couple times with a hammer and flattened it to less than half its original diameter without any cracking. I guess this rules out a zinc problem?

So, I'm reconsidering casting some bullets myself. My spousal critter is opposed to using the oven to heat-treat lead, so I'm waiting for a chance to try that on a sample of my lead bricks when she's not around. :D

Assuming they don't harden when water dropped, my plan was to try something like this: melt one brick (25#) with half a pound of tin, two pounds of 70%lead/30%antimony hardening alloy, and something like 2.5 pounds or 5 pounds of the magnum shot (which amount is the question of my OP), make ingots from that and test water-drop hardening of that alloy (which, if my calculations are correct, should be about 2% antimony from the hardening alloy + a little from the shot), so that should work if there is enough arsenic, right?

Assuming that works, I'd probably try mixing that alloy and the original brick alloy one to one and test heat treatment again. If the second alloy failed to water harden, that would indicate that my bricks have little or no antimony, or I'd run out of arsenic.

243winxb

October 29, 2013, 11:39 PM

http://www.lasc.us/heattreat.htm I thought Arsenic was in all lead?? If i dont know whats in the alloy, i cast a few bullet to see what i get. Weight & diameter as bullets drop from the mold help identifying the alloy. My thumb nail tells me the hardness.

Buck13

October 30, 2013, 03:07 AM

I'd read that, but apparently not absorbed it. Sounds like I need at least twice the Sb that I was thinking of for effective heat treatment.

What is the Sb content of magnum shot? Does shot formulation vary by size??

USSR

October 30, 2013, 08:41 AM

Buck13,

The formulation you listed using 5 pounds of the magnum shot will get you an alloy that will work fine for hardening. Here is what it works out to:

Lead - 95.7%; Antimony - 2.62%; Tin - 1.54%; and Arsenic - .19%.

Don

Buck13

November 1, 2013, 03:30 PM

Thanks very much. That sounds like it might be workable, or at least a good place to start playing.

What formulation did you use for the shot in that calculation?

USSR

November 1, 2013, 03:45 PM

93.75% lead, 5% antimony, and 1.25% arsenic.

Don

Buck13

November 1, 2013, 05:37 PM

Thanks again. I'll record that in my notebook.

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